JPH1145916A - Tester and testing method for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance testing under a wafer state by providing each probe mounting means with specified number of signal wires for transmitting signals from a semiconductor tester. SOLUTION: In the tester for a semiconductor wafer, an X, Y, Z moving mechanism is mounted on a part for mounting a probe substrate. Consequently, a wafer stage and means for mounting a wafer on a wafer chuck can be simplified in structure. Since the probe board is lighter than the wafer chuck, moving load of the X, Y, Z moving mechanism is also light and motors required for movement can be reduced in size. The probe board is dedicated for a single device to be measured and provided with probes only for a single device. Wiring with the probe board is also limited to a single device. A wafer probing mechanism of such a structure can deal with maximum number of simultaneous testing by the tester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a semiconductor wafer test apparatus, and more particularly, to an improved semiconductor wafer test apparatus capable of improving test performance in a wafer state. Related. The present invention also relates to a method for testing a semiconductor wafer, which has been improved so that test performance in a wafer state can be improved.

[0002]

2. Description of the Related Art FIG. 2 is a perspective view of a conventional semiconductor wafer test apparatus. For testing in a wafer state, a wafer prober is usually used. The wafer prober uses X,
It has a function of mounting a suction plate called a wafer chuck on which Y and Z movement mechanisms are mounted, and sequentially moving the wafer chuck by a set movement amount in accordance with a movement command. As shown in FIG. 2, the space between the tester and the wafer prober is mainly composed of a test head, a probe card interface board attached to the test head, a probe needle substrate, a probe needle, wiring, and the like.

[0003] The test head is provided with pins for all signals exchanged between the tester and the device.
The probe card interface board is mounted to make electrical contact between the pins on the test head and the probe needle substrate. The probe needle substrate is provided with needles for contacting device test pads on the wafer, and the connection wires on the probe needle substrate are used to electrically connect the needles to the pins of the test head. Pins and needles are wired.

[0004] Further, since the tester is usually equipped with a function capable of simultaneously testing a plurality of devices, even in the test of a wafer state, in order to reduce the total test time of the wafer, one tester is required.
A plurality of devices in a wafer can be tested at the same time. For this reason, the pins for connection wiring of the probe needle substrate are mounted for the number of signals corresponding to the maximum number of devices that the tester can test at one time. Further, the probe needles on the probe needle substrate are configured so that the needles of the simultaneous test device are mounted, and the needles contact a plurality of devices at once. Further, the needle for each device is connected to a corresponding pogo pin on the test head through a pin for connection wiring on the probe needle substrate and a probe card interface board.

[0005]

By the way, in the conventional apparatus, when the wafer diameter increases or the wafer shape changes, it is necessary to change the wafer prober to a wafer prober prepared according to the standard each time. Occurs. Also,
Although multiple devices in one wafer can be tested at the same time,
Multiple wafers cannot be tested simultaneously. For example, assume that a wafer has a potential defect due to a defect during the manufacturing process. To detect this, potential failures can only be found after measuring the device to some extent. During that time, the other wafers are still waiting for testing, and until the wafer containing the defect is rejected,
The next wafer cannot be mounted on the test equipment, causing a time loss. In addition, the time required to transfer a wafer to a test apparatus cannot be ignored, and when a plurality of wafers cannot be tested at the same time, it is simply added to the wafer processing time, which increases the test time for one lot in total. Has also become.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to improve a semiconductor wafer test which can improve test performance in a wafer state. It is intended to provide a device.

It is another object of the present invention to improve a test performance in a wafer state.
An object of the present invention is to provide a method for testing a semiconductor wafer.

[0008]

According to a first aspect of the present invention, there is provided a semiconductor wafer testing apparatus including a plurality of probing stations for testing a semiconductor wafer. Each of the probing stations includes: (a) a wafer test table for arranging the wafer to be tested; (b) probe needle mounting means for mounting a probe needle for bringing the wafer into contact with the wafer; XYZ moving means mounted on the probe needle mounting means for moving the probe needle in the X-axis, Y-axis, and Z-axis directions. Each of the probe needle mounting means is provided with a signal wiring for transmitting a signal from the semiconductor test apparatus for one device.

The semiconductor wafer testing apparatus according to claim 2 further includes means for preventing a test of another probing station from being interrupted even when a test of a wafer is stopped at a specific probing station.

In the semiconductor wafer testing apparatus according to the third aspect, each probing station is connected by a communication cable, and when all the probing stations have the same size and the same shape, only one probing station is connected. There is further provided a means for enabling the setting of all the other probing stations to be the same by simply setting.

In the semiconductor wafer testing apparatus according to a fourth aspect, each probing station further includes means for individually designating a device position on a wafer to be tested first.

In the method for testing a semiconductor wafer according to a fifth aspect, first, a wafer testing apparatus having a plurality of probing stations for testing wafers one by one is prepared. A wafer to be evaluated is placed in each of the probing stations. The wafers are tested simultaneously at each of the probing stations.

[0013] In the method for testing a semiconductor wafer according to claim 6, in a specific probing station,
Even when the test of the semiconductor wafer is stopped, the test of the semiconductor wafer is performed at another probing station.

In the method for testing a semiconductor wafer according to claim 7, each probing station is connected by a communication cable, and when all the probing stations have the same size and the same shape, only one probing station is connected. Just set it, and set all other probing stations to the same setting.

In the method for testing a semiconductor wafer according to the present invention, the starting positions of the devices of the semiconductor wafer to be tested are individually set at each probing station.

According to the present invention, an X, Y, Z moving mechanism is provided at a portion where the probe needle is mounted, and the conventional wafer prober itself is a mechanism for mounting a wafer on a wafer chuck, and the wafer diameter is reduced. Even when the wafer shape changes, the prober itself is not affected. Since the operation such as wafer alignment is performed by the probe needle mounting unit, X,
If a configuration capable of sufficiently securing the movement amounts of Y and Z is adopted, a change in the wafer can be handled by software control.

At the time of simultaneous testing of a plurality of devices, a wafer prober having a maximum number of simultaneous tests that can be tested by a tester is installed, and each wafer prober has a probe needle and a probe needle substrate for one device and a probe card interface corresponding thereto. By performing wiring to the board, a configuration for simultaneous testing of a plurality of wafers can be realized with one device / one prober. Even when a wafer reject is required due to a defect in the manufacturing process, the processing can be performed smoothly. In addition, since alignment of a wafer, which has required a long time, can be performed on a plurality of wafers in parallel, the processing time can be reduced. The X, Y, and Z movement mechanisms can be configured by using a mechanism mounted on a conventional wafer prober, or by combining a general horizontal movement apparatus, a vertical movement apparatus, and the like.

[0018]

Embodiment 1 Figure 1 [OF THE PREFERRED EMBODIMENTS OF THE INVENTION implementation is a perspective view of a semiconductor wafer test apparatus according to the first embodiment. In the conventional wafer test apparatus shown in FIG.
The X, Y and Z moving mechanisms are mounted below the wafer chuck. All cables from the tester main body are supplied from the probe card interface board to the probe needle board through the test head. Probe needles for contacting the device to be measured are mounted on the probe needle substrate in a number required for the simultaneous test. Wiring for electrical connection is provided between the wiring pins on the probe needle substrate and the probe needles. At the time of a wafer test, the probe needle and the device to be measured are electrically connected, so that signals can be transmitted and received between the tester and the device, and a device test can be performed in a wafer state. Device replacement on a wafer is performed by moving the wafer itself by an X, Y, Z movement mechanism.

On the other hand, in the semiconductor wafer test apparatus according to the first embodiment shown in FIG. 1, unlike the conventional apparatus, X, Y, Z
Is not mounted below the wafer chuck, but is mounted on the portion where the probe needle substrate is mounted.
For this reason, the structure of the wafer stage and the means for mounting the wafer on the wafer chuck can be simplified because a mechanism for accurately moving the wafer is not required.

Further, since the probe needle substrate is lighter in weight than the wafer chuck, the moving load on the X, Y, Z moving mechanism is light, and the motors required for moving can be miniaturized. In addition, when the wafer diameter is increased or the wafer shape is changed, the wafer alignment cannot be performed as it is, but it can be dealt with by changing the movement control included in the X, Y, and Z movement mechanisms. The mechanism that includes does not need to be changed. For this reason, it is not necessary to remodel the wafer chuck and the means for mounting the wafer on the wafer chuck, which have been conventionally required. The probe needle substrate used is dedicated to one device to be measured, and only one probe needle is mounted.

Further, the wiring to the probe needle substrate is also provided for only one device. A wafer probing mechanism having this configuration is prepared for the maximum number of simultaneous tests that can be measured by the tester, and each probing station corresponds to a device number assigned at the time of the simultaneous test. For example, probing station # 1 corresponds to simultaneous test device number 1, and probing station #n corresponds to device number n.

In this configuration, the number of simultaneous tests per wafer is limited to one, but the number of wafers that can be measured simultaneously can correspond to the maximum number of simultaneous test devices that the tester can test. The total number of devices that can be tested at the same time
However, in the apparatus shown in FIG. 2, the probe needles for a plurality of devices have to be set on one probe needle substrate, and the processing limitation is added. Cannot always be installed.

In addition, even when the maximum number of probe needles can be set, even in the area of a wafer at the time of wafer test, even if all of the probe needles in which the devices are set can be tested at once,
Since there is a portion near the edge of the wafer or a portion where the chip arrangement does not have a probe needle installed, an area that cannot be measured for up to several minutes in one test comes out. This phenomenon does not occur if the shape of the wafer is square or rectangular, but this phenomenon occurs in the current mainstream circular wafer because there are always devices and differences between the edge and the center of the wafer.

In the apparatus shown in FIG. 1, since each probing station has one probe needle, there is no dependence on the shape of the wafer and the above phenomenon does not occur. Therefore, when testing several wafers, the test time per wafer is shorter in the apparatus of FIG. 2, but the number of probing stations in the apparatus of FIG. In a test or the like where the number of simultaneous measurements is the same, the test time per wafer is shorter in the apparatus of FIG.

Further, in the apparatus shown in FIG. 1, a plurality of wafers can be simultaneously aligned and loaded / unloaded to / from the wafer chuck, which greatly contributes to the total wafer test time. This is because the load / unload time corresponding to the number of wafers is added to the test time in the apparatus of FIG. 2, whereas the load / unload time of one probing station is sufficient for the number of probing stations in the apparatus of FIG. .

Embodiment 2 Although the functions of the devices are the same, when the wafer shape and the chip shape are different, in the apparatus shown in FIG. 2, it is necessary to change the prober setting every time there is a difference. . However, in the configuration of the apparatus shown in FIG. 1, by providing a function for setting and registering a wafer shape and a chip shape individually for each probing station, wafers having these differences can be simultaneously tested with the same test item. Becomes possible.

Embodiment 3 In the case where the number of chips falling in a particular test item continuously drops during a wafer test and the number of chips falling in the item exceeds a certain number, an apparatus for removing the wafer by the wafer test is provided. The control to be performed may be made to be a prober. For example, suppose that some parts for probe needle contact have not been formed due to some defect in the wafer manufacturing process. This means that when a wafer test is performed, the probe needle does not come into electrical contact with the device, and all devices fail the test in the first test item. If all the devices on the wafer are tested, the test time is wasted. If the test fails for a certain number of the same items, the wafer is removed from the wafer test at that time. In the case of the apparatus shown in FIG. 2, when the wafer is removed during the test, the next wafer to be tested is set. At that time, the tester is also stopped, and the tester cannot start the test until the test preparation for the next wafer is completed.

In the apparatus shown in FIG. 1, when a wafer at a certain probing station is removed during a test, only that probing station prepares for the next wafer, but if the tester is stopped at the same time, the other probing stations are stopped. In this case, processing of a normal wafer being tested is stopped, resulting in a reduction in processing efficiency. Therefore, in such a case, when the wafer at the probing station is removed during the test, the tester is not stopped, and only the test at the probing station is interrupted. Then, the tester and the probe station incorporate a sequence in which the wafer in the suspended probing station is removed and the test of the other probing station is continued while the test preparation of the next wafer is completed, and the tester stops. Eliminate time. The probing station whose test preparation for the next wafer is completed detects the next test start signal at that time from the tester and starts the wafer test. With this series of operations, even if the wafer is removed during the test, the test at the other probing stations does not need to be interrupted.

Embodiment 4 In the apparatus shown in FIG. 1, when wafers have the same size and the same shape in all the probing stations, it is necessary to perform the same setting in all the probing stations. Therefore, a function is provided in which only one probing station is set by setting a communication cable between each probing station and all other probing station settings are the same.

Fifth Embodiment In the apparatus shown in FIG. 1, a function for individually designating device positions on a wafer to be tested first is mounted at each probing station, so that only a part of devices on a specific wafer is tested. This can be realized when not performing the test, when there is a device for which it is desired not to leave the probe needle mark, or when only some devices on the wafer have already been tested and these tests are omitted. The combination with the function of the fourth embodiment is effective when testing only a plurality of wafers having the same shape, and it is necessary to set only the test start device position for each probing station.

[0031]

According to the semiconductor wafer test apparatus of the present invention, the X, Y, and Z movement mechanisms are provided on the probe card, and the wafer chuck is not provided with the movement mechanism. Even when the diameter increases, there is an effect that it is not necessary to replace the wafer prober. Also, the card mounting portion has a structure in which signal wirings for only one device are gathered from the tester head. By installing a plurality of devices having this mechanism, there is an effect that simultaneous tests can be performed within a range not exceeding the maximum number of simultaneous testers.

According to the semiconductor wafer test apparatus of the second aspect, even when the test of the wafer is stopped at the specific probing station, the effect of not stopping the test of the other probing stations can be obtained.

According to the semiconductor wafer testing apparatus of the third aspect, it is possible to simultaneously test wafers having the same chip function and different chip sizes and shapes under the same test item.

According to the semiconductor wafer testing apparatus of the present invention, when all the wafers to be tested have the same shape and the start coordinates of the test chips are different for each wafer, an arbitrary start coordinate is set for each probing mechanism. This has the effect of setting the

According to the method for testing a semiconductor wafer according to the fifth aspect, there is an effect that wafers having the same chip function and different chip sizes and shapes can be tested simultaneously with the same test item.

According to the semiconductor wafer test method of the present invention, even when the test of the semiconductor wafer is stopped at a specific probing station, the test of the semiconductor wafer can be performed at another probing station. It works.

According to the semiconductor wafer testing method of the present invention, when all the wafers to be tested have the same shape, 1
By setting one probing mechanism, there is an effect that all the settings of the other probing mechanisms can be matched.

According to the semiconductor wafer test method of the present invention, when all the wafers to be tested have the same shape,
In addition, when the start coordinates of the test chips are different for each wafer, it is possible to set an arbitrary start coordinate for each probing mechanism.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor wafer test apparatus according to a first embodiment.

FIG. 2 is a perspective view of a conventional semiconductor wafer test apparatus.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomoya Kawagoe 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (8)

[Claims] 1. A semiconductor device comprising: a plurality of probing stations for testing a semiconductor wafer, wherein each of the probing stations comprises: (a) a wafer test table for arranging the wafer to be tested; and (b) contacting the wafer. (C) XYZ moving means mounted on the probe needle mounting means for moving the probe needle in the X-axis, Y-axis, and Z-axis directions, A semiconductor wafer testing apparatus, wherein each of the probe needle mounting means is provided with a signal wiring for transmitting a signal from the semiconductor wafer testing apparatus for one device. 2. The semiconductor wafer test apparatus according to claim 1, further comprising means for preventing a test of another probing station from being interrupted even when a test of the wafer is stopped at a specific probing station. 3. When each probing station is connected by a communication cable, and the semiconductor wafers have the same size and the same shape in all the probing stations,
2. The semiconductor wafer test apparatus according to claim 1, further comprising means for setting only one probing station and setting all other probing stations to the same setting. 4. In each probing station,
2. The semiconductor wafer test apparatus according to claim 1, further comprising: means for individually specifying device positions on a wafer to be tested first. 5. A step of preparing a wafer testing apparatus having a plurality of probing stations for testing wafers one by one; a step of arranging a wafer to be evaluated in each of the probing stations; and a step of each of the probing stations. And testing the wafers simultaneously. 6. The method for testing a semiconductor wafer according to claim 5, wherein the test of the semiconductor wafer is performed at another probing station even when the test of the semiconductor wafer is stopped at a specific probing station. 7. Probing stations are connected by a communication cable, and when the semiconductor wafers have the same size and the same shape in all the probing stations,
6. The semiconductor wafer testing method according to claim 5, wherein only one probing station is set, and all other probing stations are set to be the same. 8. At each probing station,
The method for testing a semiconductor wafer according to claim 5, wherein the start position of each device of the semiconductor wafer to be tested is set individually.